This method is for the determination of pentane-insoluble matter in petroleum oils and is applicable to samples that are reasonably fluid at 37 C or lower temperatures. This method covers the range of 0.01% to about 20% pentane-insolubles. Solid particulate materials interfere. More viscous or solid materials such as asphalts may be handled by the modification described in the APPENDIX. The data provided by this method may be employed as an index to the coking tendency of petroleum oils when considering their suitability as charge stocks to cracking or other processes.

Since asphaltenes are commonly defined as the material present in oil fractions that is not soluble in light paraffinic solvents, usually pentane or heptane, this method determines pentane-insoluble asphaltenes while UOP Method 614 determines heptane-insoluble asphaltenes.